gravity speed bikes

general rules all classes

1. Max Weight: 34 Kg / 75 lb.s Max weight is for bike ONLY. 2. Max Wheelbase: 127 cm / 50 in. (front axle center to aft axle center) Stock Speed Bike. No restrictions in Unlimited classes 3. Wheels: Max Diameter: 51 cm / 20 in. in Stock Speed Bike classes No restrictions in Unlimited Speed Bike classes Design: 3 spoke minimum Wheel Covering: Disk wheel covers are allowed on rear wheels ONLY in stock classes. Both in Unlimited classes allowed. 4. Tyre's: No restrictions MUST be in good condition. 5. Handlebars: Design is open to the builder/rider. Design must prove no danger to rider. 6. Seat: Design and position is open to builder/rider. Design must prove no danger to rider. 7. Foot Pegs: Minimum diameter 3 cm / 1 3/16 in. 8. Ballast: Solid weight ballast is permitted. MUST be secured to the gravity bike frame via structural fasteners or welding. No ballast is permitted to be carried on riders body 9. Frames: All chassis' and frames must be structurally sound and free of rust and defects. Frames may be either "box" or "round" in design. See bike classes for further verification here. 10. Brakes: All style/design Gravity Bikes must have working front and rear brakes. Disc brakes are HIGHLY recommended, however not mandatory. The basic requirement for any braking system is that the rider MUST be able to bring the Gravity Bike to a full stop, from a speed of 100kph/60mph, within 100m/300ft. Custom braking systems are permitted, however it is up to the rider to prove the braking ability of the custom braking. 11. Protective Gear: Helmet: MUST be full face. Helmets must certified. (example, DOT, SNELL, etc.) MUST be in good condition. The use of aerodynamic shells that fit over the helmet are ALLOWED. Aerodynamic additions to helmet are allowed if proven to be easily removed or broken off on impact so as to not cause an injury of any description to the wearer. Leathers: MUST be one (1) piece or two (2) piece that zips together at waist. Must be of good condition. Aerodynamic additions that can be removed easily or broken off on impact so not to cause any injury of any description to rider is permitted, such as Styrofoam. May be attached using Velco or similar technique/materials. Gloves: Must be leather or material that offers same protection. Shoes: Must be secure fitting. Must provide ankle protection. Low cut allowed ONLY if there is additional ankle protection is worn. Additional Gear: Elbow, shin, and knee padding or armor is RECOMMENDED. Not mandatory. Speedsuits: Are ALLOWED. Must be worn over top of leathers.

Starting Procedures: Upright gravity speed bikes, seated kick start is allowed. NO running starts. Fully enclosed and recumbent style gravity speed bikes, the use of spotters to aid in balance of the bike/rider during rollup is allowed. Spotters are allowed to touch bike/rider during rollup until balance is obtained. Spotters in no way can add any forward thrust during the rollup process.

the gravity speed bike classes

Stock Speed Bike NF (non-faired)

Defined as any bike that utilizes a traditional and/or commercially manufactured 'BMX Frame' as the structural component or frame of the gravity bike. The use of any aerodynamic fairings and/or any aerodynamic devices is NOT permitted.

Unlimited Speed Bike NF (non-faired) Defined as any bike that utilizes a unique specifically or deliberately manufactured custom frame as the structural basis of the bike or any frame other than a traditional or commercially available BMX frame. Recumbent frames allowed.

Custom Gravity Bike by the virtue of their design, can typically include, rear swing arms and/or fork components as required by their design. *Note: The use of structural aero tubing is allowed in frame and fork construction.

The use of any aerodynamic fairings and/or aerodynamic devices is NOT permitted

Stock Speed Bike F (faired). Defined as any bike that utilizes a traditional and/or commercially manufactured 'BMX Frame' as the structural component or frame of the gravity bike. The use of any aerodynamic fairings and/or any aerodynamic devices is ALLOWED, as defined by Stock Speed Bike fairing classifications below.

Unlimited Speed Bike F (faired)Defined as any bike that utilizes a unique specifically or deliberately manufactured custom frame as the structural basis of the bike or any frame other than a traditional or commercially available BMX frame. Custom Gravity Bike frames can be manufactured to resemble traditional BMX frames, but will not be classified as a Stock Speed Bike. Recumbent style frames are permitted. Aero tubing allowed. Custom Gravity Bike by the virtue of their design, can typically include, rear swing arms and/or fork components as required by their design. The use of any aerodynamic fairings and/or aerodynamic devices is ALLOWED, and there are NO restrictions on design or dimension. Full enclosure fairings are permitted.

Stock Speed Bike Fairing Classifications:

Full fairings or Motorcycle Style fairings that enclose both the ‘front’, ‘side’ and ‘underneath’ of a bike and rider and are only permitted to be used in the “Fairing” classes as outlined. Their mounting position, design and shape are at the rider’s discretion.

Front mini fairings are only permitted to be used in the “Fairing” classes as outlined. Front mini fairings are to be no larger than 23cm/10 inches X 30.5cm/12 inches. Their mounting position, design and shape are at the rider’s discretion.

Rear fairings are only permitted to be used in the “Fairing” classes as outlined. When used, the rear fairing cannot exceed the width of the rider, and cannot extend further than 60cm/24 inches past the trailing edge of the rear tyre, with a maximum width or 15cm/6 inches. Their mounting position, design and shape are at the rider’s discretion.

Enclosed frame fairings are only permitted to be used in the “Fairing” classes as outlined. Enclosed Frame Fairings are to be no larger than 23cm/10 inches X 30.5cm/12 inches on either side of the bike frame. Their mounting position, design and shape are at the rider’s discretion.

Side fairings or kneelers fairings are those fairings which provide aerodynamic advantage in front of a riders knees and are only permitted to be used in the “Fairing” classes as outlined. Side Fairings or Kneeler Fairings are to be no larger than 23cm/10 inches X 30.5cm/12 inches on either side of the bike frame. Their mounting position, design and shape are at the rider’s discretion

WGSA DISCLAIMER: There are by no means the guarantee of safety from the application of WGSA rules and regulations. WGSA rules and regulations are for the procedures required to record gravity speed record attempts. WGSA is solely a record keeping organization and is not liable for any property damage, injury or death of driver, participant, or official. Driver safety and vehicle safety and reliability is the sole responsibility and good judgment of the rider/driver/team attempting the speed run during a non-sanctioned record speed run attempt. The WGSA is not involved in the policing and/or the compliance of any rules and regulations involving safety at non-sanctioned WGSA speed run. The safety rules stated in this WGSA site are suggestions and recommendations for the rider/driver/teams to consider when running outside of a WGSA sanctioned event.